WASHINGTON -- The State Department is urging the Chinese government to release arrested family members of a Muslim dissident in exile in the United States.

"We are deeply concerned by reports that three of Rebiya Kadeer's adult children were detained and one or more may have been beaten," McCormack said. "We will continue to urge that they be allowed to move and act freely."

An Amnesty International official said one of those arrested is 4 years old.

Chinese authorities detained the family members to keep them from talking to a U.S. congressional team visiting the Xinjiang autonomous region, the Uyghur American Association said Tuesday. The 8 million Uyghurs are the largest Muslim ethnic group in Xinjiang in northwestern China, and they are ethnically related to central Asians, not Chinese.

"The practice of going after Rebiya Kadeer's family members, it's nothing new," said T. Kumar, Amnesty International's advocacy director for Asia and the Pacific.

But Kumar, who has spoken with the family, said Kadeer had expected her kin to be released when the congressional team left the region. Instead, Kumar said, two of Kadeer's sons were moved to a camp outside Xinjiang's capital city, Urumqi, and beaten.

"One of them is hospitalized, and the rest are under house arrest. We don't know where they are," Kumar said. The youngest of those arrested is only 4 years old, he said.

Kadeer, once a prominent businesswoman, was arrested in 1999 in Xinjiang on her way to meet U.S. government researchers. She was sentenced to eight years in prison but was given early release in March 2005 and allowed to leave for the United States.